Method of making an article comprising polysulfide rubbers

ABSTRACT

The use of polysulfide rubbers cured with zinc oxide and tetramethylthiuram disulfide and other sulfur containing cure accelerators for polyisoprene rubbers in hot applied processes and articles formed thereby are disclosed. The compositions are useful as hot applied sealants and in the extrusion of hoses and similar rubber articles.

BACKGROUND OF THE INVENTION

This invention relates to the art of polysulfide polymers, more particularly to thiol terminated liquid polysulfide polymers and hot melt applications, such as, hot melt applied sealants, extrusion of hoses and the like.

The use of liquid thiol terminated polysulfide polymer in caulks, sealants and the like for numerous applications is well known. Such materials have normally, until now, been chemically cured in situ.

When rapid cure was desired, a two part system was necessary requiring mixing with proper equipment just before use. One part chemical cure, on the other hand, was satisfactory in avoiding the need for in situ mixing but inherently was a slower cure requiring that provision be made for time to reach structural integrity, in some uses requiring provision of storage facilities, support racks and the like. In production applications, the extra space and/or equipment required by either cure mechanism added a cost factor whose elimination would be considered desirable by those skilled in the art.

Hot melt applied materials offer the potential to eliminate both the two part chemical cure requirement of in situ mixing and the lengthy holding requirement of one part chemical cure.

Although polysulfide rubbers are classified along with most other natural and synthetic rubbers as thermosplastic materials, they have always been considered by the art as sharing the property of most rubbers that, once vulcanized, heating to the point at which plastic flow is possible, would cause irreversible degradation of the polymeric chain and that, upon cooling, the resulting properties would be far poorer. Illustrative of the thermal degradation process is an article by Bertozzi in Rubber Chemistry and Technology, Vol. 41 (1968) p. 114 at pages 128 through 130.

The ability to formulate a cured polysulfide rubber in such fashion that the good mechanical properties characteristic of polysulfide rubbers in general is retained after extrusion under heat and pressure is thus unexpected.

Cure of thiol terminated liquid polysulfide polymers with zinc compounds including zinc oxide and tetraalkylthiuram polysulfides is disclosed by Canadian Pat. No. 907,793, Aug. 15, 1972. The further inclusion of sulfur in this cure system is disclosed in U.S. Pat. No. 3,637,574, Jan. 25, 1972. Copies of both patents accompanying this application for the examiner's convenience.

Neither patent suggests that the cured compositions disclosed therein will have hot plastic flow properties different from other known cured polysulfide rubbers.

SUMMARY OF THE INVENTION

The invention provides a process for the preparation of a formed article of manufacture comprising a cured rubber based on a thiol terminated liquid polysulfide polymer cured with zinc oxide and a sulfur containing compound selected from 2-mercaptobenzothiazol, zinc diloweralkyldithiocarbamate, and alkyl thiuram polysulfides of the formula I: ##STR1## wherein x is from about 2 to about 6 and R' is alkyl of from 1 to about 10 carbon atoms either straight chain, branched chain or cyclic or R' moieties attached to the same nitrogen atom may be concatenated and taken together with said nitrogen atom to form a heterocyclic ring, which comprises:

(a) extruding said cured rubber through a die under heat and pressure; and

(b) allowing the extruded rubber of step (a) to cool and solidify.

The invention also provides a process for the preparation of an article of manufacture comprising a substrate having a cured rubber based on a thiol terminated liquid polysulfide polymer cured with zinc oxide and a sulfur containing compound selected from 2-mercaptobenzothiazol, zinc diloweralkyldithiocarbamate, and alkyl thiuram polysulfides of the formula I on at least one surface thereof, which comprises:

(a) extruding said cured rubber through a die under heat and pressure onto at least one surface of a substrate; and

(b) allowing said extruded rubber of step (a) to cool and solidify.

The invention also provides a cured rubber based on a thiol terminated liquid polysulfide polymer, said cured rubber being in condition to under go plastic flow under pressure with substantial recovery of its preflow physical properties on cooling, comprising a thiol terminated liquid polysulfide polymer cured with zinc oxide and a sulfur containing compound selected from 2-mercaptobenzothiazol, zinc diloweralkyldithiocarbamate, and alkyl thiuram polysulfides of the formula I said cured polymer being maintained at a temperature of from about 220° F. to about 390° F.

The invention also provides a curable composition comprising a thiol terminated liquid polysulfide polymer, zinc oxide and a sulfur containing compound selected from 2-mercaptobenzothiazol, zinc diloweralkyldithiocarbamate, and alkyl thiuram polysulfides of the formula I and one or more extrudability improvers selected from copolymers of styrene with alkylenes, organic or inorganic reinforcing fibrous materials, phenolic resins, coumarone-indene resins, antioxidants and heat stabilizers for rubbers, polyalkylene polymers, factice, terpene resins, terpene resin esters, benzothiazyl disulfide, or diphenyl guanidine.

The extrudate produced by the processes of the invention possesses the inherent applied use characteristic while in the flowable state of being able to wet concrete, glass, aluminum, ceramic, wood and other common architectural materials, forming good bonds to such surfaces when cool, thus evidencing usefulness as a hot applied sealant for insulating glass window sandwiches, for windows in vehicles for rail and highway travel, in the prefabrication of building components and the like.

DESCRIPTION OF THE PREFERRED EMBODIMENT

The manner of making and using the compositions and processes of the invention will now be described with reference to a specific embodiment thereof; namely, a cured rubber (III) based on a thiol terminated liquid polysulfide polymer of the general formula: ##STR2## wherein n is sufficient to give an average molecular weight of about 7500 and containing about 0.5% random crosslinking introduced by incorporation of trichloropropane in the original polysulfide polymer condensation and cured with zinc oxide and tetramethylthiuram disulfide.

To prepare III, II may be blended in conventional mixing equipment, conveniently in such fashion as to avoid entrainment of air in the blend, with a curing amount of zinc oxide, conveniently about 2 parts by weight (pbw) to about 25 pbw per hundred pbw liquid polysulfide polymer, preferably from about 3 pbw to about 10 pbw, and an effective amount of tetramethylthiuram disulfide, conveniently from about 0.1 pbw to about 50 pbw per hundred pbw of liquid polysulfide polymer, preferably from about 0.5 pbw to about 10 pbw. The blended polymer and curing agents may then be formed into any desired shape by conventional techniques; such as, casting in a mold or extrusion as a tape and cured either at room temperature or obviously more quickly at elevated temperatures, such as, about 70° C.

One skilled in the art will recognize that in addition to the thiol terminated liquid polysulfide polymer II illustrated herein above, other polysulfide polymers of the general formula: ##STR3## wherein n is 4 up to a value sufficient to give a molecular weight of about 10,000, which may be uncrosslinked or contain up to about 2% crosslinking and wherein R is a hydrocarbon, oxahydrocarbon or thiahydrocarbon diradical such as the ethylene radical

    --CH.sub.2 CH.sub.2 --

the butylene radical

    --CH.sub.2 CH.sub.2 CH.sub.2 CH.sub.2 --

the diethylether diradical

    --CH.sub.2 CH.sub.2 OCH.sub.2 CH.sub.2 --

the diethylformal diradical

    --CH.sub.2 CH.sub.2 OCH.sub.2 OCH.sub.2 CH.sub.2 --

and the like will be suitable for the preparation of compounds suitable for use in the processes of the invention.

U.S. Pat. No. 2,466,963 teaches the synthesis of this type of polymer. A number of these polymers are commercially available from Thiokol Corporation.

In the processes for the use of the compositions of the invention, their application by the use of conventional equipment is contemplated. For example, a cured ribbon of I may be extruded under heat and pressure from a heated screw-type extruder gun. Their use in replacing currently used chemically cured polymers, as well as current hot applied materials and mechanical supports or secondarily applied chemically cured supporting compositions, are contemplated. For example, I may be extruded as above directly into edges of a channel between two pieces of window glass. Upon cooling, the unit so formed will be mechanically strong enough for further processing.

The temperatures employed for hot melt application will be those commonly employed in conventional hot melt processing; desirably they will be sufficient to cause relatively easy plastic flow from the extrusion equipment without being excessively high so as to cause obvious decomposition or reversion to a permanent liquid in a small test sample. Conveniently, these temperatures will range from about 220° F. to about 390° F., preferably about 250° to about 375° F., most preferably about 250° to 350° F.

In preparing the compositions of the invention, the incorporation of standard additives similar to those already employed in analogous compositions in the relevant art area is contemplated. These will include fillers such as calcium carbonate, barium sulfate, neutral clays and the like, pigments and opaquing agents such as titanium dioxide and carbon black, thixotropic flow control agents as, for example, the proprietary castor oil derivative THIXCIN GR and adhesion promotors such as the silane adhesion promoter A-187.

It has additionally been found that the inclusion of certain other additives in hot melt formulations of thiol terminated polysulfide polymers cured with zinc oxide and compounds of formula I or in hydroxy terminated polysulfide rubbers results in improvement in the extrudability of the formulated materials and in the post extrusion properties.

Typical of these materials are copolymers of styrene with alkylenes such as isoprene, ethylene, and butylene; various reinforcing fibrous materials, both organic and inorganic, such as polyethylene fibers, phenolic resins, coumarone-indene resins, organic and inorganic antioxidants and known heat stabilizers for rubbers; polyalkylene polymers such as polyisobutylenes; factice; terpene resins and terpene resin esters. Benzothiazyl disulfide and diphenyl guanidine are also additives useful as extrudability improvers. The use of such optional additives is contemplated by the formulations of the invention both in the specification and in the appended claims.

While the use of sulfur containing compounds in combination with zinc oxide for the preparation of cured polysulfide rubber suitable for use in the processes of the invention has been illustrated using tetramethylthiuram disulfide, it will be obvious to one skilled in the art that other sulfur containing compounds which are known sulfur containing vulcanization accelerators for polyisoprene rubbers such as 2-mercaptobenzothiazol, zinc diloweralkyldithiocarbamates, and other alkyl thiuram polysulfides of formula I may be substituted for tetramethylthiuram disulfide in similar proportions using identical processing and cure techniques to prepare cured polysulfide rubbers possessing similar extrusion and recovery properties. Illustrative of zinc diloweralkyldithiocarbamates are those compounds of the general formula: ##STR4## wherein R" is a straight chain, branched chain, or cyclic hydrocarbon radical of from 1 to about 8 carbon atoms, such as methyl, ethyl, hexyl and the like. These compounds are commercially available or are readily synthesized by well known procedures.

In addition to tetramethylthiuram disulfide, compounds illustrative of formula I are tetraethylthiuram disulfide, tetraamylthiuram disulfide, tetradecyclthiuram disulfide, tetraoctylthiuram disulfide, tetracyclohexylthiuram disulfide, dipentamethylenethiuram tetrasulfide, dipentamethylenethiuram hexasulfide and the like. These compounds are also either commercially available or may be synthesized by well known procedures.

The following examples further illustrate the best mode contemplated by the inventor for the practice of his invention.

EXAMPLE 1

Sealant formulations suitable for insulated glass use are formulated from the ingredients shown below in the table with the respective quantities given in parts by weight (pbw). Processing is performed in conventional sealant mixing equipment and the mixtures are allowed to cure in the form of tapes at room temperature. Physical properties and "gunning" properties are determined on the cured material with the results also shown below in the table.

    ______________________________________                                                         Formulation                                                                    No. (Quantity pbw)                                             Ingredient        1       2       3     4                                      ______________________________________                                         Polysulfide polymer II                                                                           100     100     100   100                                    Calcium carbonate  80      80      80    80                                    CHLOROWAX 70 (chlorinated                                                                         25      25      25    25                                    paraffin-Diamond                                                               Shamrock Co.)                                                                  THIXCIN GR (castor oil                                                                           8       8       8     8                                      derivative-National                                                            Lead)                                                                          A-187 (silane adhesive                                                                           2       2       2     2                                      additive-Union Carbide)                                                        Zinc Oxide        5       5       2.5   --                                     1:1 pbw Levulinic Acid/                                                                          2       2       2     --                                     SANTICIZER 261 (proprietary                                                    plasticizer-Monsanto Co.)                                                      Tetramethylthiuram disulfide                                                                     --      1       1     1                                      Processability (Baker Perkins                                                                    all very good                                                Mixer-Room Temp.)                                                              Shore A Hardness after                                                                           no      40      30    25                                     Room Temp. Cure   cure                                                         Gunnability at 375° F.                                                                    not     excel-  excel-                                                                               ex-                                                      gun-    lent    lent  cel-                                                     nable                 lent                                   Wetting of glass and                                                                             --      excel-  excel-                                                                               ex-                                    aluminum at 375° F.                                                                               lent    lent  cel-                                                                           lent                                   Shore A Hardness after                                                                           still   38      35    25                                     cooling           liquid                                                                         after                                                                          1 week                                                       ______________________________________                                    

EXAMPLE 2

Additional formulations suitable for use as window sealants are prepared, cured and tested in a fashion analogous to that of Example 1. The formulations in pbw and results obtained are shown in the table below.

    __________________________________________________________________________                           Formulation No. (Quantity pbw)                           Ingredient            1  2  3  4  5  6  7  8                                   __________________________________________________________________________     Polysulfide Polymer II                                                                               100                                                                               100                                                                               100                                                                               100                                                                               100                                                                               100                                                                               100                                                                               100                                 KRATON G1107 (Styrene-Isoprene-Styrene                                                                13                                                                               -- -- 6  7  -- -- --                                  Block Copolymer - Shell Chemical Co.)                                          BaSO.sub.4 (Barytes)   80                                                                                80                                                                                80                                                                                80                                                                                80                                                                                80                                                                                80                                                                                80                                 CHLOROWAX 70           25                                                                                25                                                                                25                                                                                25                                                                                25                                                                                25                                                                                25                                                                                25                                 Carbon Black          -- -- -- -- 0.5                                                                               0.4                                                                               0.4                                                                               0.4                                 Zinc Oxide            5  5  5  5  5  5  5  5                                   A-187                 2  2  2  2  2  2  2  2                                   1:1 pwb Levulinic Acid/SANTICIZER 278*                                                               2  -- -- 1  -- -- -- --                                  Fluffy polyethylene fiber                                                                            1  3  1.5                                                                               -- -- -- -- --                                  Tetramethylthiuram disulfide                                                                         1  1  1  1  1  1  1  1                                   Factice               -- -- -- -- -- --  10                                                                               --                                  Coumarone Indene Resin (CUMAR R-16 -                                                                 -- -- -- -- -- -- -- 5                                   Allied Chemical Corp.)                                                         __________________________________________________________________________      *(proprietary plasticizer  Monsanto Co.)                                 

    Formulation No.                                                                 Property             1  2  3  4  5  6  7  8                                   __________________________________________________________________________     Processability (Baker Perkins Room Temp.)                                                            all samples O.K.                                         Gunnability.sup.(1) (300° F.)                                                                 6  6  1.sup.(2)                                                                         5  4  2  3  3                                   Gunnability  (325° F.)                                                                        -- -- -- -- -- 2  2  --                                  Gunnability  (375° F.)                                                                        6   2.sup. (2)                                                                       1.sup. (3)                                                                        --  2.sup. (3)                                                                        5.sup. (3)                                                                       -- --                                  Wettability.sup.(1) (300° F.)                                                                 6  6  1  5  4  2  3  3                                   Hardness (Shore A) After Cure                                                                        38 24 27 22 35 30 31 29                                  Hardness (Shore A) 3 days after 300° F. Gun.                                                  20 (3)                                                                               (3)                                                                               35 30 31 37 28                                  __________________________________________________________________________      Notes:                                                                         .sup.(1) Index for Gunnability and Wettability: 1 =  superior; 2 =             excellent; 3 = very good; 4 = good; 5 = fair; 6 = poor; 7 = very poor          .sup.(2) partial reversion to liquid state                                     .sup.(3) complete reversion to liquid state.                             

Formulations 2, 4 and 6 are repeated. After treatment in Baker Perkins mixer only and cure, the following results are found.

    ______________________________________                                                         Formulation No.                                                Property          2        4        6                                          ______________________________________                                         Gunnability at 300° F.                                                                     2        3        2                                         Wettability at 300° F.                                                                     2        3        2                                         Shore A 1 day     35       25       30                                         Shore A 1 week    35       27       31                                         ______________________________________                                         The formulations are                                                           then put through a hot rubber mill with the following results:                                 Formulation No.                                                Property          2        4        6                                          ______________________________________                                         Gunnability 300° F.                                                                       4         4        2                                         Wettability 300° F.                                                                       4         4        2                                         Shore A (1 day)    20.sup.(4)                                                                             22       25                                         Shore A (1 week)   20.sup.(4)                                                                             22       22                                         ______________________________________                                          Note:                                                                          .sup.(4) = Tacky feel                                                    

EXAMPLE 3

Thermoplastic rubber based sealant formulations are prepared analogously to Example 1 from the ingredients shown and the properties of the cured formulations determined.

    ______________________________________                                                      Formulation No. (Quantity pbw)                                                 1    2      3      4    5    6                                    ______________________________________                                         Ingredient                                                                     Polysulfide Polymer II                                                                        100    100    100  100  100  100                                KRATON G 1107  6      --     --   6    --   --                                 KRATON G 1650                                                                  (styrene                                                                       ethylene butylene)                                                                            --     6      --   --   6    --                                 (block copolymers-Shell)                                                       KRATON G 4600 (Chem. Co.)                                                                     --     --     6    --   --   6                                  CHLOROWAX 70    25     25     25   25   25   25                                BaSO.sub.4 (Barytes)                                                                           80     80     80   80   80   80                                Zinc Oxide     4      4      4    6    6    6                                  Levulinic Acid/                                                                SANTICIZER 278 (1:1)                                                                          2      2      2    --   --   --                                 Tetramethylthiuram                                                                            1      1      1    1    1    1                                  disulfide                                                                      Properties                                                                     Processability at 200° F.                                                              Fair for all samples                                            Work Life      All samples set up in mixer                                     Hardness                                                                       (Shore A) Before Gun.                                                                         45     45     45   25   35   25                                 Gunnability at 375° F.                                                                 Fair for all samples                                            Wettability at 375° F.                                                                 Fair for all samples                                            Hardness                                                                       (Shore A) after cool                                                                          30     25     35   30   30   30                                 ______________________________________                                    

EXAMPLE 4

Thermoplastic rubber based sealant formulations are prepared analogously to Example 1 from the ingredients in the quantities shown in the table below. Properties of the cured preparations are determined and listed.

    __________________________________________________________________________                         Formulation No. (Quantity (pbw)                                                1  2  3  4  5  6  7  8  9  10                              __________________________________________________________________________     Ingredient                                                                     Polysulfide Polymer II                                                                             100                                                                               100                                                                               100                                                                               100                                                                               100                                                                               100                                                                               100                                                                               100                                                                               100                                                                               100                             KRATON G 1107       7  5  3  1  7  5  3  1  3  3                               CHLOROWAX 70         25                                                                                25                                                                                25                                                                                25                                                                                25                                                                                25                                                                                25                                                                                25                                                                                25                                                                                25                             BaSO.sub.4 (Barytes)                                                                                80                                                                                80                                                                                80                                                                                80                                                                                80                                                                                80                                                                                80                                                                                80                                                                                80                                                                                80                             Zinc Oxide          5  5  5  5  5  5  5  5  5  5                               A-187               2  2  2  2  2  2  2  2  2  2                               Levulinic Acid/SANTICIZER 178 (1:1)                                                                2  2  2  2  -- -- -- -- 2  --                              Tetramethylthiuram disulfide                                                                       1  1  1  1  1  1  1  1  -- 2                               Properties                                                                     Processability      Fair for all samples                                       Work Life (Min.)    (1)                                                                               (1)                                                                               (1)                                                                               (1)                                                                                 5                                                                                5  5  5 (2)                                                                                5                              Cure Time (Room Temp. Min.)                                                                        (1)                                                                               (1)                                                                               (1)                                                                               (1)                                                                               10 10 10 10 (2)                                                                               10                              Tackfree Time (Room Temp. Min.)                                                                    (1)                                                                               (1)                                                                               (1)                                                                               (1)                                                                               15 15 20 20 (2)                                                                               20                              Hardness (Shore A) Before Gun                                                                      25 25 40 20 20 25 25 20 -- 15                              Gunnability at 375° F.                                                                      exc.                                                                              good                                                                              poor                                                                              exc.                                                                              exc.                                                                              fair-                                                                             fair-                                                                             fair-                                                                             -- good                                                               good                                                                              good                                                                              good                                  Wettability at 375° F.                                                                      exc.                                                                              good                                                                              poor                                                                              exc.                                                                              exc.                                                                              fair-                                                                             fair-                                                                             fair-                                                                             -- good                                                               good                                                                              good                                                                              good                                  Hardness (Shore A) After Gun.                                                                      24 22 37 24 25 20 20 20 -- 15                              Adhesion to glass (type of failure).sup.(3)                                                        coh                                                                               coh                                                                               adh-                                                                              coh                                                                               adh                                                                               adh                                                                               coh                                                                               adh                                                                               -- adh                                                       coh                                                  Adhesion to alum. (type of failure)                                                                coh                                                                               coh-                                                                              adh-                                                                              coh                                                                               adh                                                                               adh                                                                               coh                                                                               coh                                                                               -- adh                                                    adh                                                                               coh                                                  __________________________________________________________________________      Notes:                                                                         .sup.(1) set up mixer                                                          .sup.(2) no cure                                                               .sup.(3) coh = cohesive failure (failure in sealant bead); adh  adhesive       failure (failure at joint between sealant and substrate); where both type      are indicated, predominant mode of failure listed first. Even adhesive         failures in these tests showed a strong bond to substrate before failure.

EXAMPLE 5

Thermoplastic rubber based sealant formulations are prepared analogously to Example 1 from the ingredients shown in the quantities tabulated below. The properties of the formulations are also indicated.

    ______________________________________                                                      Formulation (Quantity pwb)                                                       1      2      3    4    5    6                                  ______________________________________                                         Ingredient                                                                     Polysulfide Polymer II                                                                        100    100    100  100  100  100                                KRATON G 1007  --     2      5    7.5   10   20                                BaSO.sub.4 (Barytes)                                                                           80     80     80   80   80   80                                CHLOROWAX 70    25     25     25   25   25   25                                Carbon black (Sterling S)                                                                     0.4    0.4    0.4  0.4  0.4  0.4                                Zinc Oxide     5      5      5    5    5    5                                  Tetramethylthiuram                                                                            1      1      1    1    1    1                                  disulfide                                                                      Properties                                                                     Processability (Baker                                                          Perkins Mixer) at 280° F.                                                              good   (poor dispersion)                                        Hardness Shore A (1 day)                                                                      22     22     23   23   22   23                                 Processability                                                                 (Hot-2 roll mill)                                                                             (fair)                                                          Hardness Shore A (1 day)                                                                      --     25     25   25   25   27                                 Gunnability (300° F.)                                                                  exc.   fair   poor poor poor poor                               Wettability (300° F.)                                                                  exc.   fair   poor poor poor poor                               Gunnability (350° F.)                                                                  exc.   exc.   exc. exc. exc. exc.                               Wettability (350° F.)                                                                  exc.   exc.   exc. exc. exc. exc.                               Adhesion to glass                                                                             adh/   adh.   adh. adh. adh. adh.                                              coh           film film film film                               Hardness after gunning                                                                        31     31     31   31   31   31                                 (Shore A)                                                                      ______________________________________                                                      Formulation No.                                                                1    2      3      4    5    6                                    ______________________________________                                         Stress/strain properties (pressed out 10 min/287° F.)                   Tensile (psi)  110    130    110  120  150  175                                Elongation (%) 300    370    340  400  510  780                                Modulus 100%    74     75     69   69   76   78                                300%           110    110    109  105  118  120                                Hardness (Shore A)                                                                             35     40     36   37   40   38                                ______________________________________                                    

EXAMPLE 6

Thermoplastic rubber based sealant compositions are formulated analogously to Example 1 from the ingredients shown in the quantities tabulated below. The physical properties of the formulation are tabulated also.

    __________________________________________________________________________                         Formulation (Quantity pbw)                                                     1  2   3   4   5   6                                       __________________________________________________________________________     Ingredient                                                                     Polysulfide Polymer II                                                                             100                                                                               100 100 100 100 100                                     Fluffy Polyethylene fibers                                                                         3  1.5 --  3   1.5 --                                      CHLOROWAX 70         25                                                                                25  25  25  25  25                                     BaSO.sub.4 (Barytes)                                                                                80                                                                                80  80  80  80  80                                     Zinc Oxide          5  5   5   5   5   5                                       Levulinic Acid/SANTICIZER 278 (1:1)                                                                2  2   2   --  --  --                                      A-187               2  2   2   2   2   2                                       Tetramethylthiuram disulfide                                                                       1  1   1   1   1   1                                       Properties                                                                     Processing at 200° F.                                                                       All samples processed satisfactorily                       Work Life at 200° F.                                                                        All samples set up in mixer                                Hardness (Shore A) before gun.                                                                     45 35  25  45  40  30                                      Gunnability at 375° F.                                                                      good                                                                              excellent                                               Wettability at 375° F.                                                                      good                                                                              excellent                                               Hardness (Shore A) after gun.                                                                      25 30  25  35  35  15                                      Adhesion to aluminum                                                                               no strong                                                                             strong                                                                             adh.                                                                               adh.                                                                               strong                                                      adh.                                                                              adh.                                                                               adh.        adh.                                    Adhesion to glass   adh.-                                                                             strong                                                                             coh.                                                                               strong                                                                             strong                                                                             coh.                                                        coh                                                                               adh.    adh.                                                                               adh.                                        __________________________________________________________________________

EXAMPLE 7

Thermoplastic rubber based sealants are formulated analogously to Example 1 from the ingredients shown in the quantities tabulated below. Physical properties of the formulations are also tabulated.

    __________________________________________________________________________                    Formulation (Quantity pbw)                                                     1  2  3  4  5  6  7  8  9  10 11 12 13  14  15                  __________________________________________________________________________     Ingredient                                                                     Polysulfide Polymer II                                                                        100                                                                               100                                                                               100                                                                               100                                                                               100                                                                               100                                                                               100                                                                               100                                                                               100                                                                               100                                                                               100                                                                               100                                                                               100 100 100                 KRATON G 1107  -- 6  2  -- 6  2  -- 6  2  -- 6  2  --  6   2                   CK-2400*       -- -- -- 2  2  2  8  8  8  -- -- -- --  --  --                  CK-2432*       -- -- -- -- -- -- -- -- -- 2  2  2  8   8   8                   CaCO.sub.3      80                                                                               -- --  80                                                                               -- --  80                                                                               -- --  80                                                                               -- --  80 --  13                  Barytes        --  80                                                                                 80                                                                              --  80                                                                                80                                                                               --  80                                                                                80                                                                               --  80                                                                                80                                                                               --   80  80                 A-187          2  2  2  2  2  2  2  2  2  2  2  2  2   2   2                   Zinc Oxide     5  5  5  5  5  5  5  5  5  5  5  5  5   5   5                   Levulinic Acid/                                                                SANTICIZER 278 (1:1)                                                                          1  1  1  1  1  1  1  1  1  1  1  1  1   1   1                   Tetramethylthiuram disulfide                                                                  1  1  1  1  1  1  1  1  1  1  1  1  1   1   1                   Properties                                                                     Processability at 200° F.                                                              all processed satisfactorily; all set up in mixer               Gunnablity at 375° F.                                                                  (3)                                                                               (3)                                                                               (3)                                                                               (3)                                                                               (3)                                                                               (3)                                                                               (1)                                                                               (1)                                                                               (1)                                                                               (1)                                                                               (1)                                                                               (1)                                                                               (1) (1) (1)                 Wettability at 375° F.                                                                 (3)                                                                               (3)                                                                               (3)                                                                               (3)                                                                               (3)                                                                               (3)                                                                               (3)                                                                               (3)                                                                               (3)                                                                               (3)                                                                               (3)                                                                               (3)                                                                               (3) (3) (2)                 Adhesion to glass                                                                             all adhesive failure                                            Adhesion to aluminum                                                                          all adhesive failure                                            __________________________________________________________________________      Notes:                                                                         *Non Heat Reactive Phenolic Resin  Union Carbide                               (1) = good;                                                                     (2) = fair;                                                                   (3) = poor                                                               

EXAMPLE 8

Thermoplastic rubber based sealant formulations are prepared analogously to Example 1 from the ingredients shown in the quantities tabulated below. Physical properties of the formulation are also tabulated.

    ______________________________________                                                         Formulation (Quantity pbw)                                                     1    2      3      4    5                                      ______________________________________                                         Ingredient                                                                     Polysulfide Polymer II                                                                           100    100    100  100  100                                  Barytes            80     80     80   80   80                                  CHLOROWAX 70       25     25     25   25   25                                  Tetrakis [methylene 3-(3',5'-di-                                               tert-butyl-4'-hydroxyphenyl) pro-                                              pionate] methane                                                               (IRGANOX 1010)    --     1      1    --   --                                   Octadecyl 3-(3',5'-di-tert-butyl-                                              4'hydroxyphenyl) propionate                                                    (IRGANOX 1076)    --     --     --   1    1                                    KRATON G1107      --     --     6    --   6                                    A-187             2      2      2    2    2                                    Zinc Oxide        5      5      5    5    5                                    Levulinic Acid/SANTICIZER                                                                        1      1      1    1    1                                    278 (1:1)                                                                      Tetramethylthiuram disulfide                                                                     1      1      1    1    1                                    Properties                                                                     Initial Hardness (Shore A)                                                                        35     25     35   25   25                                  Gunnability (375° F.)                                                                     exc.   exc.   exc. good exc.                                 Wettability (375° F.)                                                                     exc.   exc.   exc. fair exc.                                 Hardness after cool (Shore A)                                                                    30     20     30   25   15                                   Hardness (Shore A) 375° F.                                              1 minute          15     25     27   19   26                                   2 minutes         12      0     25   19    0                                   3 minutes          9      0     19   16    0                                   Appearance @ 375° F.                                                    1 minute          OK     OK     OK   OK   OK                                   2 minutes         (1)    soft   OK   OK   soft                                 3 minutes         (2)    soft   (1)  (1)  soft                                 5 minutes         reverted                                                     Bead Adhesion                                                                  Glass (after 1 wk. exp. H.sub.2 O)                                                               coh    coh    coh  coh  coh                                  Aluminum (after 1 wk. exp. H.sub.2 O)                                                            coh    coh    coh  coh  coh                                  ______________________________________                                          Note:-                                                                         (1) slightly soft                                                              (2) slightly reverted                                                    

EXAMPLE 9

Thermoplastic rubber based sealant formulations are prepared analogously to Example 1 from the ingredients shown in the quantities tabulated below. Physical properties of the formulations are also tabulated.

    ______________________________________                                                      Formulation (Quantity pbw)                                                     1    2      3      4    5    6                                    ______________________________________                                         Ingredient                                                                     Polysulfide polymer II                                                                        100    100    100  100  100  100                                Barytes         80     80     80   80   80   80                                CHLOROWAX 70    25     25     25   25   25   25                                IRGANOX 1010   3      3      --   --   --   --                                 IRGANOX 1076   --     --     3    3    --   --                                 Magnesium oxide                                                                               --     --     --   --   5    5                                  KRATON G 1107  --     6      --   6    --   6                                  A-187          2      2      2    2    2    2                                  Zinc Oxide     5      5      5    5    5    5                                  Tetramethylthiuram                                                             disulfide      1      1      1    1    1    1                                  Physical Properties                                                            Initial Hardness (Shore A)                                                                     20     18    5    5    5    5                                  Gunnability at 375° F.                                                                 exc.   exc.   exc. exc. exc. exc.                               Stability at 375° F.                                                    1 min. Hardness (Shore A)                                                                      10     15     10   15   20  5                                  3 min. Hardness (Shore A)                                                                     5       10     10  5     10  5                                  5 min. Hardness (Shore A)                                                                     0      0      0    0    0    0                                  ______________________________________                                    

EXAMPLE 10

Thermoplastic rubber based sealant formulations are prepared analogously to Example 1 from the ingredients shown in the quantities tabulated below. Physical properties of the formulation are also tabulated.

    __________________________________________________________________________                         Formulation (Quantity pbw)                                                     1  2  3  4  5  6  7                                        __________________________________________________________________________     Ingredient                                                                     Polysulfide polymer II                                                                             100                                                                               100                                                                               100                                                                               100                                                                               100                                                                               100                                                                               100                                      KRATON G 1107       -- -- -- 2  2  -- 7                                        Barytes              80                                                                                80                                                                                80                                                                                80                                                                                80                                                                                80                                                                                80                                      CHLOROWAX 70         25                                                                                25                                                                                25                                                                                25                                                                                25                                                                                25                                                                                25                                      Vistanox LM-MS (polyisobutylene-Exxon)                                                             --  10                                                                                25                                                                                10                                                                                25                                                                               -- --                                       Vistanox L-140 (polyisobutylene-Exxon)                                                             -- -- -- -- -- 5  5                                        A-187               2  2  2  2  2  2  2                                        Zinc Oxide          5  5  5  5  5  5  5                                        Tetramethylthiuram disulfide                                                                       1  1  1  1  1  1  1                                        Properties                                                                     Processability at 200° F. (Baker Perkins                                                    exc.                                                                              fair                                                    mixer)                                                                         Hardness (Shore A) after process.                                                                  25 15 25 25 15 -- --                                       Gunnability at 375° F.                                                                      exc.                                                                              exc.                                                                              good                                                                              good                                                                              good                                                                              -- --                                       Gunnability at 300° F.                                                                      exc.                                                                              -- -- -- -- exc.                                                                              good                                     Wettability at 375° F.                                                                      exc.                                                                              exc.                                                                              good                                                                              good                                                                              good                                                                              exc.                                                                              good                                     Wettability at 300° F.                                                                      exc.                                                                              -- -- -- -- exc.                                                                              good                                     __________________________________________________________________________

EXAMPLE 11

Thermoplastic rubber based sealant formulations are prepared analogously to Example 1 from the ingredients shown in the quantities tabulated below. Physical properties of the formulations are also tabulated.

    __________________________________________________________________________                         Formulation (Quantity pbw)                                                     1  2  3  4  5  6  7                                        __________________________________________________________________________     Ingredient                                                                     Polysulfide polymer II                                                                             100                                                                               100                                                                               100                                                                               100                                                                               100                                                                               100                                                                               100                                      Barytes              80                                                                                80                                                                                80                                                                                80                                                                                80                                                                                80                                                                                80                                      CHLOROWAX 70         25                                                                                25                                                                                25                                                                                25                                                                                25                                                                                25                                                                                25                                      KRATON G 1107       -- 2  -- -- 7  -- --                                       Thermoplastic phenolic resin                                                   CK 2432 - Union Carbide                                                                            2  2  -- -- -- -- --                                       Factice             -- --  10                                                                                20                                                                                15                                                                               -- --                                       Cumarone-Indene resin - CUMAR R16 -                                            Neville Chem. Co.   -- -- -- -- -- 5   10                                      A-187               2  2  2  2  2  2  2                                        Zinc oxide          5  5  5  5  5  5  5                                        Tetramethylthiuram disulfide                                                                       1  1  1  1  1  1  1                                        Properties                                                                     Gunnability at 375° F.                                                                      good                                                                              good                                                                              fair                                                                              exc.                                                                              exc.                                                                              -- --                                       Gunnability at 300° F.                                                                      -- -- -- exc.                                                                              exc.                                                                              exc.                                                                              exc.                                     Wettability at 375° F.                                                                      good                                                                              good                                                                              fair                                                                              exc.                                                                              exc.                                                                              -- --                                       Wettability at 300° F.                                                                      -- -- -- exc.                                                                              exc.                                                                              exc.                                                                              exc.                                     Hardness (Shore A) before gun.sup.(1)                                                              25 25 30 15 15 30 30                                       Hardness (Shore A) after gun.sup.(1)                                                               25 15 30 30 20 19 20                                       __________________________________________________________________________      Note:                                                                          .sup.(1) All hardness readings are instantaneous as values drift.        

EXAMPLE 12

Thermoplastic rubber based sealant formulations are prepared analogously to Example 1 from the ingredients shown in the quantities tabulated below. Physical properties of the formulation are also tabulated.

    __________________________________________________________________________                         Formulation (Quantity pbw)                                                     1  2  3  4  5  6  7  8                                     __________________________________________________________________________     Ingredient                                                                     Polysulfide polymer II                                                                             100                                                                               100                                                                               100                                                                               100                                                                               100                                                                               100                                                                               100                                                                               100                                   Barytes              80                                                                                80                                                                                80                                                                                80                                                                                80                                                                                80                                                                                80                                                                                80                                   CHLOROWAX 70         25                                                                                25                                                                                25                                                                                25                                                                                25                                                                                25                                                                                25                                                                                25                                   Carbon black        0.4                                                                               0.4                                                                               0.4                                                                               0.4                                                                               0.4                                                                               0.4                                                                               0.4                                                                               0.4                                   Polyterpene resin (ZONAREZ 7115                                                Arizona Chem. Co.)  5   10                                                                               -- -- -- -- -- --                                    Polyterpene resin (ZONAREZ B-40                                                Arizona Chem. Co.)  -- -- 5   10                                                                               -- -- -- --                                    Resin ester (Zonester 55, Arizona                                              Chem. Co.           -- -- -- -- 5   10                                                                               -- --                                    Resin ester (Zonester 85, Arizona                                              Chem. Co.           -- -- -- -- -- -- 5   10                                   A-187               2  2  2  2  2  2  2  2                                     Zinc oxide          5  5  5  5  5  5  5  5                                     Tetramethylthiuram disulfide                                                                       1  1  1  1  1  1  1  1                                     Physical Properties                                                            Hardness before gun. (Shore A).sup.(1)                                                             35 35 20 30 30 30 30 30                                    Gunnability at 300° F.                                                                      exc.                                                                              exc.                                                                              exc.                                                                              exc.                                                                              exc.                                                                              exc.                                                                              exc.                                                                              exc.                                  Wettability at 300° F.                                                                      exc.                                                                              exc.                                                                              exc.                                                                              exc.                                                                              exc.                                                                              exc.                                                                              exc.                                                                              exc.                                  Hardness (Shore A) 1 day after gun.sup.(1)                                                         15 10 10 10 20 20 15 15                                    Hardness (Shore A) 14 days after gun.sup.(1)                                                       28 23 25 27 28 27 24 24                                    __________________________________________________________________________      Note:                                                                          .sup.(1) Instantaneous readings  all samples tend to drift while measure.

EXAMPLE 13

Sealant formulations based on thermoplastic rubber are formulated from the ingredients tabulated, in the quantities shown in parts by weight as in the previous examples. Properties determined on the cured formulation are also tabulated.

    ______________________________________                                         Ingredient            Quantity (pbw)                                           ______________________________________                                         Polysulfide polymer II                                                                               100                                                      CHLOROWAX 70          25.0                                                     BaSO.sub.4 (Barytes)  80.0                                                     A-187                 2.0                                                      Carbon Black          0.4                                                      Benzothiazyl disulfide                                                                               0.3                                                      Diphenyl guanidine    0.1                                                      Zinc oxide            5.0                                                      Tetramethylthiuram disulfide                                                                         1.3                                                      ______________________________________                                    

Properties

Mixing--excellent

Work life--1 hour

Cure time (Room Temp)--5 hours

Tack free time (Room Temp)--5 hours

Hardness before extrusion (Shore A)--10

Hardness after 7 days (Shore A)--25

Gunnability at 250° F.

Standard extrusion conditions (Hardenmann "P" Shooter)-excellent Hardness after extrusion (Shore A)

1 hour--15

1 day--25

7 days--25

Determination of effect of dwell time in gun on hardness of thoroughly cooled extrudate and of ease of extrusion

After hold temp 1 min. excellent extrudability

Hardness on cooling (Shore A)--20

After hold temp. 3 min. excellent extrudability

Hardness on cooling (Shore A)--20

After hold temp. 5 min. excellent extrudability

Hardness on cooling (Shore A)--15

After hold temp. 10 min. excellent extrudability Hardness on cooling (Shore A)--13

Adhesion

1 day after extrusion (room temperature)

Glass--cohesive

Aluminum--cohesive

7 days after extrusion (room temperature--water submergence)

Glass--cohesive

Aluminum--cohesive

EXAMPLE 14

Sealant formulations based on thermoplastic rubber are formulated from the ingredients tabulated, in the quantities shown in parts by weight as in the previous examples. Properties determined on the cured formulations are also tabulated.

    __________________________________________________________________________                     Formulation (Quantity pbw)                                                     1  2  3  4  5  6  7  8                                         __________________________________________________________________________     Ingredient                                                                     Polysulfide polymer II                                                                         100                                                                               100                                                                               100                                                                               100                                                                               100                                                                               100                                                                               100                                                                               100                                       BaSO.sub.4       80                                                                                80                                                                                80                                                                                80                                                                                80                                                                                80                                                                                80                                                                                80                                       CHLOROWAX 70     25                                                                                25                                                                                25                                                                                25                                                                                25                                                                                25                                                                                25                                                                                25                                       A-187           2  2  2  2  2  2  2  2                                         Zinc Oxide      5  5  5  5  5  5  5  5                                         Carbon black    0.4                                                                               0.4                                                                               0.4                                                                               0.4                                                                               0.4                                                                               0.4                                                                               0.4                                                                               0.4                                       Dipentamethylenethiuram                                                        hexasulfide     1  2.5                                                                               -- -- -- -- -- 1                                         Zinc dimethyldithiocarbamate                                                                   -- -- 2.5                                                                               -- -- -- -- --                                        Tetraethylthiuram disulfide                                                                    -- -- -- 1  2.5                                                                               -- -- --                                        Tetramethylthiuram disulfide                                                                   -- -- -- -- -- 1   0.75                                                                             --                                        2-mercaptobenzothiazole                                                                        -- -- -- -- --  0.75                                                                             1  --                                        p-quinone dioxime                                                                              -- -- -- -- -- -- -- 0.5                                       Diphenyl guanidine                                                                             -- -- -- -- -- -- -- 0.5                                       Properties                                                                     Gunnability at 300° F.                                                                  exc.                                                                              v.gd.                                                                             exc.                                                                              exc.                                                                              exc.                                                                              exc.                                                                              exc.                                                                              good                                      Hardness (Shore A)                                                             Before Gunning  32 31 32 27 34 17 12 33                                        After Gunning   30 30 32 25 32 20 22 30                                        __________________________________________________________________________ 

The subject matter which applicant regards as his invention is particularly pointed out and distinctly claimed as follows:
 1. A process for the preparation of a formed article of manufacture comprising a cured rubber based on a thiol terminated liquid polysulfide polymer cured with zinc oxide and a sulfur containing compound selected from 2-mercaptobenzothiazol, zinc diloweralkyldithiocarbamate, and alkyl thiuram polysulfides of the formula ##STR5## wherein x is from about 2 to about 6 and R" is alkyl of from 1 to about 10 carbon atoms either straight chain, branched chain or cyclic or R' moieties attached to the same nitrogen atom may be concatenated and taken together with said nitrogen atom to form a heterocyclic ring, which comprises:(a) extruding said cured rubber through a die under heat and pressure; and (b) allowing the extruded rubber of step (a) to cool and solidify.
 2. A process for the preparation of an article of manufacture comprising a substrate having a cured rubber based on a thiol terminated liquid polysulfide polymer cured with zinc oxide and a sulfur containing compound as defined in claim 1 on at least one surface thereof, which comprises:(a) extruding said rubber through a die under heat and pressure onto at least one surface of a substrate; and (b) allowing the extruded rubber of step (a) to cool and solidify.
 3. A process as defined in claim 1 wherein the cured rubber additionally contains one or more extrudability improvers selected from copolymers of styrene with alkylenes, organic or inorganic reinforcing fibers, phenolic resins, coumaroneindene resins, antioxidants and heat stabilizers for rubbers, polyalkylene polymers, factice, terpene resins, terpene esters, benzothiazyl disulfide, or diphenyl guanidine.
 4. A process as defined in claim 3 wherein the extrudability improver is a styrene-isoprene-styrene block copolymer.
 5. A process as defined in claim 3 wherein the extrudability improver is a mixture of benzothiazyl disulfide and diphenyl guanidine.
 6. A process as defined in claim 2 wherein the cured rubber additionally contains one or more extrudability improvers selected from copolymers of styrenes with alkylenes, organic or inorganic reinforcing fibers, phenolic resins, coumaroneindene resins, antioxidants and heat stabilizers for rubbers, poly alkylene polymers, factice, terpene resins, terpene esters, benzothiazyl disulfide, or diphenyl guanidine.
 7. A process as defined in claim 6 wherein the extrudability improver is a styrene-isoprene-styrene block copolymer.
 8. A process as defined in claim 6 wherein the extrudability improver is a mixture of benzothiazyl disulfide and diphenyl guanidine.
 9. A process as defined in claims 1, 2, 3, 4, 5, 6, 7 or 8 wherein the sulfur containing compound is 2-mercaptobenzothiazol.
 10. A process as defined in claims 1, 2, 3, 4, 5, 6, 7 or 8 wherein the sulfur containing compound is zinc diloweralkyldithiocarbamate.
 11. A process as defined in claim 10 wherein the zinc diloweralkyldithiocarbamate is zinc dimethyldithiocarbamate.
 12. A process as defined in claims 1, 2, 3, 4, 5, 6, 7 or 8 wherein the sulfur containing compound is a compound of the formula: ##STR6## wherein x is from about 2 to about 6 and R' is alkyl of from 1 to about 10 carbon atoms either straight chain, branched chain or cyclic or R' moieties attached to the same nitrogen atom may be concatenated and taken together with said nitrogen atom form a heterocyclic ring.
 13. A process as defined in claim 12 wherein R' is methyl and x is
 2. 14. A process as defined in claim 12 wherein R' is ethyl and x is
 2. 15. A process as defined in claim 12 wherein the R' pairs bonded to a common nitrogen atom are concatenated to form a pentamethylene moiety and x is
 6. 